Sensors comprising electrodes, a track and an electrical connector are used extensively in the assessment of clinical condition, for example, without limitation, in the monitoring of a cardiac condition. The electrodes are placed in contact with the skin of an individual, including, without limitation, a human body and the electrical physiological signals which result are examined. The physiological signals themselves are transported through an electrically conductive track to an electrical connector which couples with an electronic instrument for receiving, collecting, storing, processing and/or transmitting the data generated by a sensor. Such data may be used to monitor and/or evaluate the health and/or physical state of a wearer.
While using a sensor can provide an accurate measurement of a signal, there are several factors that can affect the signal quality, including, without limitation, stability, noise and/or sensibility. These limitations are due, at least in part, to factors such as motion. This can be exacerbated when a sensor is included in a garment. In such a situation, the electrode and track of a sensor need to be integrated in a garment in a minimally invasive manner that allows, for example, without limitation, flexibility, and comfort to an individual's body, including in movement and be resistant to degredation due to repeated washing. At the same time, a sensor must also be capable of measuring a signal accurately.
To reduce background noise, one solution has been to attach a sensor to the skin with an adhesive. An issue with such an arrangement has been the lack of comfort and the inability to reuse the sensor as it can only be applied once to an individual at which point it is usually disposed. Therefore, there is a need for a sensor that is integrated in a fabric, such as, without limitation, a garment, wherein an adhesive is eliminated and is replaced with a sensor that is applied to the skin of an individual using the fabric's pressure to the body. One way in which pressure can be created is to make a sensor flexible, elastic and with improved adhesion properties, but avoiding adhesive elements, so that it can adapt to every different type of body. This includes making the track flexible and elastic and the electrode flexible and with improved anti-slip property such that every movement made by an individual's body will be translated into an electrode and a track keeping it in place, while an individual is in motion while retaining the fidelity of the signal. To accomplish this result, a track can be constructed of a flexible and elastic conductive material, for example, without limitation, a silicone conductive rubber.
A problem facing the developers of advanced electronic textiles is how to interconnect electrical components and electronic devices with each other and with electrical connectors via electrically conductive tracks provided on the fabric substrate of an electronic garment. It is known in the field of electronic fabrics, when the substrate is a wearable, elastic and flexible garment, the integration of rigid elements creates a weakness and frequently the rigid element will break the garment when it is stretched.
With regard to a silicone conductive rubber, one issue related to the use of this material in a garment is that the garment can be damaged during the curing process. This has limited the use of silicone conductive rubber as a means to connect an electrode to an electronic connector until a means to cure it on a fabric at room. Other drawbacks of a sensor where the track is made by a semi-conductive elastic material include having a mechanically weak linkage between the track and an electrical connector when the fabric is stretched. One result is that the fabric can tear after suffering a physical stress.
The development of a sensor and a garment comprising a sensor with flexibility and elasticity which allows recording physiological signals, especially in movement, with improved adhesion properties but avoiding adhesive elements which produce skin irritations is of great interest. In addition, the development of an improved silicone conductive elastic track and electrical connector assembly in wearable fabric and a method to cure a silicone conductive rubber at room temperature, including, without limitation, on a garment, is of great interest.